The Digital Home Network Group (DHWG) is an industry alliance formed for the purpose of defining an interoperability framework for networked media devices. The DHWG has selected Universal Plug and Play (UPnP) technology to provide the necessary infrastructure to enable media transfer between different consumer devices. The UPnP networking technology provides flexibility for media configuration and transport management for consumer electronic devices. Within a home network, a device with media processing capability may use UPnP technology to facilitate its connectivity to other devices.
The current version of the UPnP AV specification defines a media server, a media renderer, and a control point. The media server has access to media content and can send that media content to other devices. The media renderer is able to receive media content and render that content. In typical implementations, the media renderer is either connected to or integrated with a display device for displaying the rendered content. The control point coordinates the operation of the media server and the media renderer in order to accomplish the desires of the end-user.
The UPnP AV specification includes a template for necessary services to manage media rendering devices and media server devices. Such services include a connection manager service, an AV transport service, and a content directory service (CDS). The connection manager service provides the methods for a control point to get sink and source capabilities of media rendering and media server devices, along with other control details. The AV transport service provides control methods for media rendering devices. The CDS service provides control methods for the media server devices as well as schema for organizing media items and their attributes.
In implementations of the CDS service, media files (e.g., audio files, video files, images, etc.) are represented as objects. The current version of the CDS specification describes a class system for representing media objects. The base class is the object class. Two classes are derived from the object class, the item class and the container class. An item (i.e., an instance of the item class) does not include any other objects. A container (i.e., an instance of the container class) may include at least one other object.
The CDS specification defines a number of classes that are derived from the item class, including an imageItem class, an audioItem class, a videoItem class, etc. The CDS specification also defines an audioBroadcast class and a videoBroadcast class. The audioBroadcast class is derived from the audioItem class. The videoBroadcast class is derived from the videoItem class. The definition of a class includes required and optional properties which may be expressed as XML elements or attributes.
A tuner is a device that is configured to access broadcast channels, such as television channels, radio channels, etc. The current version of the CDS specification does not include means for representing tuner devices. The existing methods and attributes defined in the current version of the CDS specification need additional enhancements to represent a tuner device. Accordingly, benefits may be realized by systems and methods for representing a tuner device in a content directory service that is implemented on a media server.